added set_kth_bit.cpp (#1863)

* added set_kth_bit.cpp

* updating DIRECTORY.md

* Update bit_manipulation/set_kth_bit.cpp

Co-authored-by: David Leal <halfpacho@gmail.com>

* Update bit_manipulation/set_kth_bit.cpp

Co-authored-by: David Leal <halfpacho@gmail.com>

Co-authored-by: David <Panquesito7@users.noreply.github.com>
Co-authored-by: David Leal <halfpacho@gmail.com>

DIRECTORY.md

@@ -18,6 +18,7 @@
   * [Count Of Set Bits](https://github.com/TheAlgorithms/C-Plus-Plus/blob/master/bit_manipulation/count_of_set_bits.cpp)
   * [Count Of Trailing Ciphers In Factorial N](https://github.com/TheAlgorithms/C-Plus-Plus/blob/master/bit_manipulation/count_of_trailing_ciphers_in_factorial_n.cpp)
   * [Hamming Distance](https://github.com/TheAlgorithms/C-Plus-Plus/blob/master/bit_manipulation/hamming_distance.cpp)
+  * [Set Kth Bit](https://github.com/TheAlgorithms/C-Plus-Plus/blob/master/bit_manipulation/set_kth_bit.cpp)
 
 ## Ciphers
   * [A1Z26 Cipher](https://github.com/TheAlgorithms/C-Plus-Plus/blob/master/ciphers/a1z26_cipher.cpp)

bit_manipulation/set_kth_bit.cpp

@@ -0,0 +1,79 @@
+/**
+ * @file
+ * @brief Implementation to [From the right, set the Kth bit in the binary
+ * representation of N]
+ * (https://practice.geeksforgeeks.org/problems/set-kth-bit3724/1/) in an
+ * integer.
+ *
+ * @details
+ * Given a number N and a value K. From the right, set the Kth bit in the binary
+ * representation of N. The position of Least Significant Bit(or last bit) is 0,
+ * the second last bit is 1 and so on. in it.
+ *
+ * A binary number consists of two digits. They are 0 & 1. Digit 1 is known as
+ * set bit in computer terms.
+ * Worst Case Time Complexity: O(1)
+ * Space complexity: O(1)
+
+ * @author [Aman Raj](https://github.com/aman2000raj)
+ */
+
+#include <cassert>   /// for assert
+#include <iostream>  /// for IO operations
+
+/**
+ * @namespace bit_manipulation
+ * @brief Bit manipulation algorithms
+ */
+namespace bit_manipulation {
+/**
+ * @namespace setKthBit
+ * @brief Functions for the [From the right, set the Kth bit in the binary
+ * representation of N]
+ * (https://practice.geeksforgeeks.org/problems/set-kth-bit3724/1/)
+ * implementation
+ */
+namespace set_kth_bit {
+/**
+ * @brief The main function implements set kth bit
+ * @param N is the number whose kth bit will be set
+ * @returns returns an integer after setting the K'th bit in N
+ */
+std::uint64_t setKthBit(std ::int64_t N,
+                        std ::int64_t k) {  // int64_t is preferred over int so
+                                            // that no Overflow can be there.
+
+    int pos =
+        1 << k;  // "pos" variable is used to store 1 at kth postion and
+                 // rest bits are 0. in binary representation of number 'n'
+
+    return N | pos;  // by taking or with the pos and the N we set the bit of N
+                     // at kth position.
+}
+}  // namespace set_kth_bit
+}  // namespace bit_manipulation
+
+/**
+ * @brief Self-test implementations
+ * @returns void
+ */
+static void test() {
+    // n = 10,2 return 14
+    assert(bit_manipulation::set_kth_bit::setKthBit(10, 2) == 14);
+    // n = 25,1 return 27
+    assert(bit_manipulation::set_kth_bit::setKthBit(25, 1) == 27);
+    // n = 400001,5 return 400033
+    assert(bit_manipulation::set_kth_bit::setKthBit(400001, 5) == 400033);
+    // n = 123 return 123
+    assert(bit_manipulation::set_kth_bit::setKthBit(123, 3) == 123);
+
+    std::cout << "All test cases successfully passed!" << std::endl;
+}
+/**
+ * @brief Main function
+ * @returns 0 on exit
+ */
+int main() {
+    test();  // run self-test implementations
+    return 0;
+}